theothertom wrote:IMO, the elephant in the room regarding FCEV's is infrastructure. You won't see much demand until there is a widespread production/delivery system for hydrogen.
The elephant in the room is the cost of hydrogen. Hydrogen is a battery. Energy from somewhere is used to produce hydrogen, which is then used to produce electric power using a fuel cell. The efficiency is terrible. That would be ok if the cost of the input power was low enough, the amount of stored energy was large enough, and the time before needed the energy is long enough. Think of a small hydrogen producing unit, a huge tank to hold hydrogen, and a small fuel cell to put the energy back on the wires.
Where hydrogen makes sense is in long term storage of energy. Efficiency doesn't matter much, a huge and cheap tank is the economic win.
Hydrogen for transportation only makes economic sense for aircraft and rockets. Both need huge amount of stored energy, and both are cost insensitive. Batteries are a better choice for a shorter range aircraft and cars.